A treasure trove of options is available for those who want to go beyond the staples
Thousands of books are written about them, as are poems, and there are even songs sung about the flowers we know as perennials. Perennials are the backbone of most garden designs and some container gardens, as well. Consumers adore perennials. Growers and designers, too.
In the search for the perfect perennial, consumers sometimes defer to online sources, finding those “10 best,” “15 best,” “20 best” (and so on) lists that often return to the same heralded few, bypassing a whole selection of perennials marked by outstanding qualities.
Here, we go a little further, providing a roundup of unsung perennials beloved by plant people who say these bloomers deserve a little more love for either their durability, color, form, performance — or all of the above. These underappreciated plants are here to get their due.
Groundcover, short-statured perennials
Allium amplectens (narrowleaf onion), a bulb, thrives in well-drained clay soil, wet winters and springs, and dry summers. In other words, it’s a natural for the Pacific Northwest and higher elevation areas of the West.
“It’s a short-statured, late-blooming showy Allium that looks phenomenal in mass plantings,” said Mike Ridling of Sevenoaks Native Nursery LLC (Albany, Oregon). The flowers bloom May to June in white to pink, on leafless stems, with a height of 6–12 inches.
Aquilegia canadensis ‘Little Lanterns’, a native, is a favorite of Ali Beck, production manager at JRT Nurseries (Aldergrove, BC, Canada) for its very dwarf, barely one-foot-high and wide stature, delicate foliage and red and yellow dangling flowers.
“It looks delicate but is so tough,” Beck said. “I’ve seen them growing out of rocky cliff out of a thimble of soil. It’s not as showy as the bigger ones, and it does self-seed a bit, but very demurely. It’s short-lived, which is advantageous in a self-seeding plant.”
Coreopsis auriculata ‘Elfin Gold’ (dwarf mouse-eared tickseed) is a steady, consistent bloomer of golden yellow rays, producing throughout summer on 8–10-inch-high by 10–12-inch-wide plants with slightly fuzzy deep-green leaves that can turn burgundy in fall. Slow to spread, it is easy to grow and works as an edge plant. Beck recommends it because it is drought tolerant once established.
Cotula ‘Tiffindell Gold’ works as a tough, free-blooming, evergreen lawn substitute that lasts decades, and matures at 2–4 inches high and 24–36 inches wide. Its blooms are like gold buttons. It can be mowed once a year and is virtually maintenance-free, according to Grace Dinsdale of Blooming Nursery (Cornelius, Oregon).
Dianthus alpinus (Alpine pink) is a hardy, rockery carnation, with a tight, semi-flat, low gray mound (2–4 inches high by 6–12 inches wide) and little pink flowers that smell like cinnamon. “It’s old-fashioned, out of the 1950s, and easy,” said Donna Giguere of Giguere Landscape Design (Portland, Oregon).
Dianthus ‘Pink Fire’ is a heavy summer and repeat bloomer on a gray mat, 6–8” high by 8–12” wide, and avoids splitting, as other Dianthus do, said Ben VanderWerf at JRT Nurseries. It is fragrant and drought tolerant.
Many Diascia are sold as annuals, Dinsdale said, but hardier, very drought tolerant ones are worth their perennial status for the mass of flowers — like Diascia integerrima ‘Coral Canyon’, which needs space, but will reward with 4–6-inch-wide plants bearing a mass of soft pink flowers all summer long on 12–13-inch stems. “They’re great in a rock garden,” she said.
Erigeron glaucus (seaside daisy or fleabane) is a coastal evergreen plant that Ridling believes is starting to get utilized by landscape designers for its large, 2-inch lavender-pink blooms with yellow centers, extremely short stature of 2–11 inches high by 12–24 inches wide, fall color and drought tolerance. “It will grow out of a crack with a white daisy that attracts small pollinators,” Giguere said. No watering is necessary for the spring-blooming, fine-textured perennial. Plant it anywhere you want pollinators, she said, as a groundcover under blueberries or apple trees, for instance. “They can get scrappy, but they will stay green all winter if there is no snow.”
Geum coccineum ‘Koi’ bears sprays of orange-red cup-shaped flowers, loose and open on delicate stems, above the 10 inch high by 18 inch wide plant with glossy, “ripply” foliage, almost like lettuce, VanderWerf said. The semi-evergreen mounds do well in the garden and in containers.
Heuchera micrantha (crevice alumroot) is most interesting for its dainty white flower, according to Ridling. It is versatile, surviving in semi-moist to dry applications. Flowers bloom between May and August, depending on elevation, above compact clumps of foliage 1–2 feet wide and reddish stems up to 2 feet high.
Leptinella perpusilla (brass buttons) gets a strong recommendation by Dinsdale to use as a groundcover and in places with light foot traffic.
“I’ve filled a lot of holes with it,” she said, including a long driveway in both partial shade and sun. “It stayed flat,” she said, and the 1 inch high by 12–18 inch wide plant formed a tight mass with no weeds and was maintenance-free. Blooms spring through summer.
Penstemon cardwellii is an easy-to-grow native plant with tubular violet-blue flowers from May to early August, lasting sometimes until fall, that is a pollinator and hummingbird magnet. With small, round evergreen leaves, the 4–12 inch high by 12–15 inches wide plant can be used as a groundcover, in a slab or in a rookery. It roots through nodules on the stem, grows in full sun and needs no water, unless in extreme heat.
“I have seen it die from too much water,” Giguere said.
Sedum spurium “Pink Cloud’ was selected for its hardiness, its ability to withstand heat, dryness, winters — everything, according to VanderWerf.
“When it blooms, it’s a pink could; you can’t see the plant, you can’t see the leaves,” he said. The evergreen forms a vigorous 1-2 inch high by 12-24 inches wide mat.
And Sedum spurium ‘Rhubarb’, with the same growth habit, matches a hot pink flower with a green and red-trimmed emerging leaf for a “stunning” plan,” VanderWerf said. “We’ve been taking it to shows this year, and it got a lot of notice.”
Tiarella ‘Pink Bouquet’ (foam flower) is one of VanderWerf’s favorites with multi-season interest and an alternative to the overused vinca or pachysandra. Clean maple-leaf shaped foliage emerges chocolate and turns green in summer. Masses of sweet-smelling flowers burst open on 12-inch high spikes like New Year’s sparklers and rebloom occurs through August. The leaves are semi-evergreen, and it thrives in sun and shade.
“Viola adunca (early blue violet, sand violet, Western dog violet, and hookedspur violet) forms tight tufts that bloom profusely, and is tough as can be,” Ridling said. A self-spreading native, the white, purple, and deep purple-veined flowers bloom compactly in a variety of conditions, from dry to moist, April through August, on plants approximately 3–6 inches high.
Viola ‘Etain’ (Etain violet) start blooming heavily in spring and keep reblooming, especially in mild winter conditions and even in heat.
“It just keeps going,” VanderWerf said. Yellow flowers trimmed in lavender are large and fragrant hanging above the clump-type 6–8 inches high and wide plants. Although it will survive some heat, it prefers moist soils and part shade.
Castilleja iniate (scarlet paintbrush) is different than other paintbrushes for its ability to thrive in wet-to-dry conditions and low-to-high elevations, according to Ridling. “It has a large flower for a Castilleja that is pretty showy.” It blooms May to September, reaching 8–32 inches high.
Dicentra formosa (Western bleeding heart) is easy, for people who want natives, but don’t like ferns, according to Giguere. It grows 1–2 feet in sun and shade, with light pink blooms May through July, and will grow under rhododendron. The plants are ephemeral, so the fine-textured leaves can be gone by summer, but not always.
Dryopteris erythrosora ‘Prolifica’ (autumn fern) matures to a large 2 foot high and wide, and is refined, according to VanderWerf, with glossy foliage and a delicately dissected leaf. The new foliage on the semi-evergreen fern emerges red, turns green in summer, and then copper red in fall, and then plants reproduce by underground stems.
Geranium oreganum (Oregon geranium) is a native with a showy, 2-inch bloom that fits well behind other ones, creeping up and out, on 18–30-inch-high by 6–18-inch-wide plants, according to Ridling.
Polemonium yezoense ‘Purple Rain’ (purple leaf Jacob’s ladder) produces deep purple blooms on strong stems above a mound of fern-like leaves, that emerge a bronzy maroon and turn a deeper green in summer and in shade. Beck describes it as evergreen in mild winters, and it reaches 12–23 inches high by 12–18 inches wide.
Sidalcea malviflora ssp. Virgata (rose checkermallow), with dainty, soft pink flowers, thrives in the dry conditions of Oregon summers once established, although they benefit from some moisture. It works as a cut flower, and insects and pollinators are drawn to it. It’s a long-seasoned native bloomer, from May through July, reaching up to 24 inches by 12–24 inches wide, fitting well in the front of the border, according to Ridling.
Symphyotrichum chilense (formerly Aster chilensis; Pacific aster), a native, stays low (1–3 feet high by 1–5 feet wide), never flops and blooms late with iridescent violet flowers, providing late pollen. “Plant it in a parking strip. It doesn’t need to be watered; so easy,” Giguere said.
Thermopsis gracilis (slender goldenbanner) has yellow spring and summer flowers with the distinct shape and form of its legume family, and tends to stay evergreen deep into winter. A mountain plant that thrives in the valley, it grows up to 3 feet high and is a good lupine alternative, by Ridling’s standards.
Aconitum columbianum (Columbian monkshood), in the buttercup family, has stems ranging between 2 and 6 feet, bearing palmate leaves and purple flowers with a top petal that folds, like a hood. Moisture-loving, sun-seeking plants, this native does well at all attitudes of the West and can present with flowers in yellow, white and tinged green, and blooms all summer, according to Ridling. It should be planted in areas away from pets or children, as parts of the plant are, in varying degrees, poisonous.
Arnica amplexicaulis (Clasping arnica) has daisy-like, pale yellow blooms, June through August, on single stems, with small lower leaves that drop before blooming, leaving the flower perched above a slim, erect stem. The plants prefer full sun to partial shade and need moist wet soils, pointing to its alternate common name, streambank arnica. “The tuft gets bigger and bigger to the point that it can have 100 blooms on a plant,” Ridling said, with a height of 6–30 inches.
Disporum hookeri (Hooker’s fairy bells), a native in the lily family, prefers full to partial shade and moist soil, and reproduces from slender rhizomes, with 1–3 white hanging bells appearing May through June, followed by bright red-orange fruit. It maintains a nice, full habit up to 18 inches.
Hakonechloa macra (Japanese horse grass) is a slow-growing, very hardy, shade tolerant grass that grows in a cascading mound. The color varies in sun to shade, and by cultivar, and its long leaves with wiry steams give the appearance of an arching mini bamboo, 12–36 inches high, without being invasive, according to VanderWerf .
Iris sibirica ‘Flight of the Butterflies’ is a distinct Siberian iris, with masses of small flowers from late spring to early summer, that when established look like bunches of butterflies (on 30–36 inch stems at maturity), according to Dinsdale. It prefers moister and sunnier settings, but will thrive in partial shade.
Sidalcea cusickii (Cusick’s checkermallow) is high, sturdy and easy-to-grow in riparian zones and other open moist habitats.
“Large blooms are pink, and it as an outstanding plant if you have an area where it can spread, even if in the back of other plants,” Ridling said. Blooms from May to June on 1½ –6 feet high by 8–12 inch wide plants.
Veronica gentianoides ‘Little Blues’ (Gentian speedwell) grows in a 12–18 inch, evergreen rosette with loose, 6–8 inch spikes of bright blue flower that pop larger than other Veronicas, according to Beck. Blooms spring and early summer above light green, powdery mildew resistant foliage.
Heat- and drought-tolerant perennials
Coreopsis verticillata ‘Zagreb’ is bullet-proof, surviving in hot, dry conditions, according to Dinsdale. Cheerful yellow blooms last spring through summer on 12–inch high by 18–inch wide plants that need no dividing.
Dodecatheon hendersonii (broad-leaved shooting star) has a striking flower, takes dry to moist conditions, is small, and can be tucked anywhere, according to Ridling. It blooms February to June on leafless 12–18-inch stalks, followed by leaves that go dormant.
Formerly classified as Zauschneria, Epilobium cana ‘Woody’s Peach Surprise’ (12–18 inches high by 9–18 inches wide) and Epilobium cana ‘Bowman’s’ (1½ –-2 feet high and wide), are commonly called California fuchsia or hummingbird trumpet for the attraction by the nectar-sipping birds. The gray foliage and tubular flowers that last through summer and into fall are appreciated by humans, as are the drought tolerance, the upright consistent form and the easy care.
Halimium lasianthum, sometimes called the other rock rose, has returned to the Blooming Nursery lineup. “It is a great long-term plant with low to zero maintenance, a symmetrical habit, and when it blooms, from June to August, it is covered in bright yellow flowers with a reddish blotch in the middle,” Dinsdale said. The 2–3-feet-high by 3–5-feet-wide plants are drought-tolerant, and butterflies love them.
An intergenetic cross, Halimiocistus × wintonensis ‘Merrist Wood Cream’ has all the same tough properties as H. lasianthum, with larger, felted grayish olive foliage and larger blooms, according to Dinsdale.
Helleborus argutifolius (Corsican hellebore), the largest of the species hellebores, with a holly leaf, is evergreen with shiny attractive serrated leaves on a 3 foot high by 5 foot wide low bush. It brings texture to a full sun to open shade area beyond its late winter to early summer bloom season, according to Giguere. It is more sun-tolerant than other hellebores, deer resistant and drought tolerant once established.
Leontopodium alpinium ‘Blossom of Snow’ (Edelweiss) has white flowers with a hint of yellow held high on 12–16 inch stems, contrasting with the silvery gray, narrow foliage. Beck considers it low maintenance, compact, and will rebloom in fall if cut back in summer.
Penstemon rydbergii (Meadow penstemon), a native, defies expectations in nursery settings, with its wide-ranging ability to thrive in habitats from moist to extremely dry, with some water needed in high heat situations. Ridling recommends it because it blooms May to August, depending on elevation, and grows to 8–28 inches high by 1–3 feet wide.
Rosmarinus officinalis’ Blue Spires’ was brought back into production at Blooming Nursery because of its hardiness. ‘Tuscan Blue’ and ‘Arp’ are industry standards, but Dinsdale explains that they have to be replanted every few years because they’re less winter hardy. “‘Blue Spire’ doesn’t,” she said. The tough, drought-tolerant plants bloom spring through summer, and mature 4–5 feet high by 2–3 feet wide.
Anemone × hybrida ‘Honorine Jobert’ is an old-fashioned Japanese anemone, introduced in 1858, that does well tucked into a corner, according to Giguere. The white flowers with yellow stamens, summer through fall, float on 3–4 foot stamens over plants that remain low, and grows to 12–18 inches. It gets less rambunctious than other anemones, but confine it, as it does spread. It grows in shade, and is vigorous and low maintenance.
Dinsdale said she didn’t fully appreciate Solidago rugosa ‘Fireworks’ (rough goldenrod) until last summer, when at three years, the 3 foot high by 3 foot wide drought tolerant plants were covered in tiny flowers that burst along 6-9 inch racemes, shooting in all directions. ‘Fireworks’ is a perfect name,” Dinsdale said for the long-lasting blooms that last until mid-fall.
Tracy Ilene Miller is a freelance writer and editor who covers several topics, including gardening. She can be reached at email@example.com.